YI series: Funny thing about anger
by Askre5
Summary: Donatello gets the harsh lesson where his temper can lead him as well as he learns a little bit more about himself. More than he cared to know.
1. Chapter 1

**A/N:** Story originally written and posted on 12/05/2007

Here is the first multi-chapter in the YI series. This one is a direct follow up to the one shot "Six lights, four shadows" and is the second story written for the series.

* * *

 **Disclaimer and Legal stuff:**

Teenage Mutant Ninja Turtles®, including Raphael®, Michelangelo®, Leonardo®, Donatello®, April O'Neil®, and Splinter® are registered trademarks of Viacom International Inc. Based on characters and comic books created by Peter A. Laird and Kevin B. Eastman.

I do not own them in other words.

This story is written purely as a homage to the Teenage Mutant Turtles and not meant for any commercial profit or infringement on copyright. This story will immediately be removed if Viacom International wishes so.

Other characters, Including Yo and In and the Black Turtles are © Hermann Gunnar Sigurðsson (Askre).

AU turtles in all their varety are based off the TMNT.

The story, is copyright © 2007 by Hermann Gunnar Sigurðsson (Askre).

 **Rated T for violence and torture.**

 **This story is part of the YI series and is canon to the Assassin series.**

 _Sum: Donatello gets the harsh lesson where his temper can lead him as well as he learns a little bit more about himself. More than he cared to know._

* * *

 **Chapter 1**

 _How did I get into this mess?_ Donatello slowly crawled further into his hiding place behind few crates. His right hand firmly held his broken naginata. The indigo colored mask was wrapped around his thigh to hold a bleeding wound.

Tello sneered a little when putting too much pressure on the wounded leg but managed to refrain from making a sound. He could hear the one searching for him move around. The turtle glanced at his injury; it was definitely not working in his favor right now.

He thought back to what had got him into this situation. It could only be summed into one word, anger. Donatello's sometimes bad temper had pretty much thrown him into the current situation, now wounded and hiding from a very dangerous character. His only hope was that the enemy would give up, but unfortunately, this particular one was very determined.

"I can smell your wound," the deep dark voice addressed him. "The blood trying to seep through your temporary bandage."

Donatello blinked and rechecked the mask and learned it was true, some blood was actually beginning to slip through. The turtle did his best to retie the makeshift bandage more properly.

"My master eagerly awaits you. I've alerted him to the situation, I am to bring you to him," the voice said and there was a cruel chuckle. "But I'm going to have a little fun with you first."

 _Fun? Right,_ Tello realized now more than ever where his temper had gotten him.

"It's too bad I can't recruit. I'm hoping though, one day. But oh well." Suddenly the large bulk of a dark brownish-green turtle could be seen. Tello sunk down hoping he was still out of view. The mask in the same color and his own and the enormous size was the clear identification of The Experimentor, the largest of the Black Turtles, the most cunning and devious one.

 _Please don't look down, please don't look down,_ Donatello thought and barely dared to move. Again, his mind wandered to how he had landed in his place.

This was an old run-down factory; the crates were covered in dirt and dust. Tello often came here when feeling like being somewhere alone. This was the best place for it, since the building was out of the way and there was access to the sewers inside of it. Unfortunately, Donatello had not been alone this time when arriving there. After something he had seldom done, arguing with his father.

Though Tello had a temper, he still obeyed and respected his father. Usually if Yo made an order, it was law for the big ninja. However, this time he had felt like protesting, it had not sat right with him.

Yo had been a bit shocked that Donatello had questioned him, but the older turtle tried to calm the situation down. However, Tello's temper took over and he argued right back, causing the Jonin to become a bit stern but never raised his voice one octave. His son was on verge of explosion and in the end stormed out, despite orders to stay put.

What had riled Donatello up was that Raphael was supposed to enter full Black Turtle patrols. The younger turtle had only been exposed to them by coincident few months ago. Yo felt that his second youngest son was good and ready, Tello did not agree.

* * *

 _"He's sixteen," Donatello growled not twitching at the stern look from his father._

 _"Donatello, you were younger than him when you met the Dark One for the first time. You came with us on the first patrol shortly after that," Yo explained as gently as he could but his patience was running thin._

 _"I am bigger than him. I was bigger than you were when I was fourteen. He's also just recently over that damn poison that the Experimentor scratched him with," Tello snapped causing his father to frown heavily._

 _"Donatello! I am not arguing about this, I have made the decision and it is final. Yes it is unfortunate that Raphael was exposed to them, but what is done is done," Yo said firmly._

 _Tello growled and looked at In who stood nearby. The white masked turtle woman had her arms folded, a neutral expression on her face. Though in her eyes was disappointment, but it was unclear exactly for what. Though Donatello suspected it was not in his favor._

 _"I am with your father on this one, Donatello. Yes I hate to have my children face those devils, but it cannot be helped. We need all the help we can get fighting them," she finally said._

 _"He's jus…. Ah forget it!" the large turtle snarled and turned away. He saw his brothers standing by the entrance of the dojo where the argument had taken place. Leonardo was holding frightened Michelangelo, Raphael had his head bowed barely daring to look at his second oldest brother._

 _"Donatello." Yo frowned when Tello stalked towards the entrance, clearly intending to leave._

 _"Donatello, come back here this instance!" the black-masked turtle called firmly._

 _His son didn't listen this time; he made his way out of the dojo and headed straight out of the lair._

* * *

 _Donatello removed the manhole cover and climbed into a large room of the old factory. Once fully up, the turtle closed the manhole and pulled out his naginata. There he began a vicious kata with it._

 _"Dammit he's right!" Tello growled as he hew down the bladed end._

 _"I just don't want Raph to have to face those bastards on regular bases!" The turtle stabbed the air with his weapon._

 _"That damn poison kept him weak for months!" the ninja sneered as he hammered his weapon on an old crate smashing it._

 _In his vicious workout, he didn't notice a large shadow slowly making its way towards him. The turtle swirled the naginata and took a defensive position with it. The reptile was breathing heavily as he was still a bit riled up. He turned only to see a large brownish-green fist come flying._

 _Tello just barely managed to raise his naginata to attempt blocking, but the fist smashed the wooden pole and continued. The turtle was struck on the face and thrown back. He lost one end of the weapon but still managed to hold onto the bladed end. The ninja landed harshly on the carapace and slid few meters back._

 _'Oh crap.' Donatello's eyes bulged out when seeing the large turtle smiling devilishly down at him. The Experimentor was holding the other end of his naginata. Even though it was not bladed, the broken end looked sharp._

 _"You!" Tello growled but halted as he was rising up. Now was definitely bad to be angry, striking this turtle in anger was certain doom._

 _"Yes it is me. I discovered this abandoned factory just few days ago and was mildly surprised to smell the strong scent of a turtle here. So I decided to wait and see if someone wouldn't just show up," the large reptile told him and began approaching._

 _'The manhole… dammit he's in the way,' Tello thought._

 _"All right, you found me, but you won't find me easy to grab," the ninja grunted and had managed to calm somewhat down. He remembered his father's words, be on the defensive against them. Never be the aggressor._

 _The Experimentor never lost the smile; suddenly he twirled the broken pole and charged._

* * *

Donatello tried not to cringe at the pain in his leg. The Experimentor had driven him further into the factory and away from the manhole. He had used the broken naginata to injure the ninja. Now Tello just waited for something even worse to happen.

He had already scuffled with the other turtle with no real results except getting tired and injured. The Experimentor was playing with him as a cat does with a mouse.

"Ah there you are." The large reptile grinned when spotting Tello.

 _I'm inventing communicators if I get out of this._ Donatello crawled further back as the Experimentor stepped in front of him.

The big turtle knelt down while regarding the ninja in front of him. He quickly reached forward and ripped the mask from the wound. Tello yelped as it disturbed the injury and caused it to bleed again.

"Aw, did that hurt?" the dark colored turtle chuckled sadistically and crawled closer to his victim.

Donatello wished he could sink into the wall but he was stuck. He was completely at the mercy of his tormentor. A large hand grabbed his wounded thigh and squeezed it. Tello cried out in pain.

"Hm, you certainly don't squeal. Too bad, but let's see what I can make you do," the Experimentor chuckled and moved even closer to Tello.

"W-what the hell…?" Donatello was really starting to worry what was going to happen.

Then the smaller reptile remembered his naginata. He wouldn't be able to kill the large turtle, but it was possible to delay him. All Tello had to do was getting to the manhole; it was way too small for the Experimentor.

"Well let's see first how you like this!" the ninja growled and thrust the blade of his weapon right into his tormentor's head.

The Experimentor barely managed to look surprised. He fell down as if dead, right on top of Donatello. The large heavy body pinned him to the floor, almost crushing him. Tello tried not to cry out in pain, this had done his wound no favors. The turtle knew he didn't have much time before the other one would wake up once more. Therefore, the ninja desperately tried to push the large reptile off.

Tello froze when the body began stirring instead of moving. Then the Experimentor rose up from him with a sneer. Slowly the large turtle grabbed the impaled naginata part and pulled it out with a roar. Then as his face was slowly regenerating, the behemoth glared down at the ninja.

"You are so going to suffer for this one," the Experimentor snarled and bared his jagged set of teeth.

* * *

Yo lifted up the manhole cover and made his way up into the room. After him came Leonardo and Raphael. The three turtles looked around the factory, hoping to spot Tello somewhere. The Jonin had decided to allow his hot-tempered son some time for himself before going after him. They all knew of the factory and that it was Donatello's sanctuary. Thus they usually did not intrude.

"Donatello?" Yo called finally when not seeing his son. He frowned, something was definitely wrong. The black-masked turtle looked at Leonardo who nodded, having felt the same thing.

"Hey there is something moving further inside." Raphael pointed at something far inside the factory.

"Donatello?" Yo figured it had to be his son and the three reptiles began walking into the factory, towards the movement Raph had spotted.

"My son, I know we had a disagreement regarding this, but we…" The oldest turtle halted and frowned now heavily.

"Weapons!" He ordered and grabbed for his kusari-gama. His two sons pulled out their own weapons though they were a bit confused about why.

They soon learned the reason, as they approached they saw a large silhouette of a turtle. Too large to be Tello, it was hunched over something. The creature became aware of their presence and looked up. All three turtles froze when recognizing the Experimentor.

"You!" Yo frowned even harder.

The giant turtle slowly turned towards them, carrying a devilish grin. The three ninjas froze when seeing whom he was carrying. Donatello barely clung to consciousness, he was slightly held up by the bigger reptile that had his arm firmly around him. Tello was bloodied, bruised and with bite marks all over his body.

"Let go of my son," Yo demanded, he fought hard to remain calm.

"Maybe I will, only to take you all down and bring the four of you to my master," the Experimentor said almost casually. Tello slowly and weakly turned his head towards his father and brothers. Weakly he raised his free hand towards them.

"F-father… help…" he begged before the hand slumped back down.

"I will Donatello, don't worry, I am here," Yo tried to reassure him.

"We have to get the Experimentor to drop your brother, then one of you get Donatello and make straight for the manhole," the black-masked- one whispered to his sons. He noticed the expression on Raphael. The turtle was angry.

"Raphael, I stress this and always will. Do not strike in anger, do not let rage rule your action here," the Jonin told him sternly.

"Let go of my son, if you want us, you must fight us." He turned his attention back to the Experimentor.

The large turtle narrowed his eyes and slowly dropped Tello to the floor. Then he rose to his full height, towering over them. Yo gave a motion with is head to Leonardo, his oldest son stepped to the right and began approaching from that side.

"Raphael, you try to get your brother," Yo whispered to his red masked son.

"But I…" Raphael shut up when getting a stern glare from his father.

"Raphael, I will not repeat this. Get your brother," the jonin said sharply before heading towards the Experimentor.

Leonardo charged first, pretending he was going to try for the big reptile's side. That caused the behemoth to shift a little away from Tello. This also gave the distraction Yo needed to send the chain of his weapon for their opponent.

The Experimentor growled and allowed the chain to wrap around his arm. He then pulled at it. The turtle on the other end held firmly. Now Leonardo had a little space to slice down with his sword, cutting off the left arm from the large reptile.

Yo pulled against the roaring enemy. The loss of the arm had made the big turtle very angry. Leonardo was forced to back away when a foot almost struck him. Again, the Experimentor pulled at the chain. The black-masked turtle lost his grip on the weapon in the process.

Now with both arms free, the left arm already regrowing, the big reptile hammered his fists at Leonardo who just barely managed to dodge out of the way. Yo pulled out his swords and began moving in. However, a movement to his right caught his attention.

"Raphael!" the older reptile called out when seeing his son run into the battle.

Raph had pulled Tello to the manhole but then figured he should help with the fight. He thus pulled out his sai once more and charged. Unfortunately, the Experimentor was faster this time. The large turtle grabbed his right arm and twisted it hard; they could all hear the bone break. Raphael screamed in pain.

"Leonardo, get Donatello down and home now. I'll get Raphael," Yo ordered Leo who had been on his way to aid his brother. The younger turtle sighed but did not hesitate to follow the order.

Fortune did smile a little on them, the Experimentor was still regenerating his lost limb, plus he had managed to entangle himself in the chains. Thus, he merely threw Raphael away while snapping the chains of the kusari-gama. Yo thus immediately went for his son, pulled him up and pretty much dragged him after Leonardo.

The large reptile managed to free himself from the chains and charged. Yo just barely managed to get down and cover the manhole, before the Experimentor opened it and tried to grab for him. The large turtle growled and stared after his enemies disappear down and out of reach. Even though he could probably rip the hole to make it wider, the other turtles would have by then managed to get even further away.

* * *

"It's a clean break; we only need to settle this and make a cast. It will heal easily," Yo said after examining Raphael's arm, they had stopped in the sewer tunnels after making sure they were not being followed. Leonardo had gone ahead before them with Tello whose condition was not very good.

"I-I'm sorry father… I just…" Raphael looked down.

"Now you know why we follow orders when fighting these devils," Yo said with a firm voice. His son nodded silently.

"Come, we better get home and settle your arm and aid Tello the best we can. I dare not think what other things the Experimentor might have been doing to him," the black-masked turtle said and began walking towards their home.

"I've never seen him so… scared… Tello I mean," Raphael whispered while following his father. Yo only nodded, if anything Donatello seldom showed fear when facing their dark enemies.

When they arrived home, they found little Mikey curled up in the couch and crying. In and Leonardo were in the infirmary tending to Tello. When the little turtle saw them come, he immediately jumped up and rushed to his father. Yo gently picked up the crying child. Michelangelo had no doubt been told to wait outside.

"Raphael, go into the infirmary and have them take care of your arm when they have finished with your brother," the jonin told his son. Raph nodded and entered the infirmary.

"There now, Michelangelo." Yo turned his attention to the youngest. He sat down in a recliner and gently patted his son on the carapace. "Your brother will be fine."

Yo knew though that his young son would be witnessing more such injuries. Now that their enemies were back, they would be going on Black Turtle patrols once more. They didn't always battle the Dark One and the others but when that happened, bad injuries were often very likely to occur.

Mikey had been too young to remember when they had last time come home badly wounded. By his second birthday, their enemies had disappeared back to their own world and stayed there for almost four years.

The child finally stopped crying and now just huddled silent in his father's arms. Yo began humming a little tune to help calming Mikey down. His deep voice had a soothing effect on the boy.

Finally Leonardo arrived along with In and Raphael. The turtle had now his arm in a cast and a sling. Michelangelo rose up a little in his father's arms to look at the others who were sitting down in the living room. In sat in the chair next to the recliner but the two older sons sat down in the couch.

"Donatello is sleeping now," the female turtle informed her husband who nodded. She then noticed the tearful eyes of her youngest and reached to cup his cheek.

"Your brother is fine, I'm sorry I had to let you stay outside. But we had to tend his wounds," she told him gently. Mikey shifted and reached for his mother, Yo picked him up and held him towards In. Once safely in his mother's arms, the little turtle curled up there clinging to her.

"Leonardo told me that you found him in the hands of the Experimentor," In looked at her mate with a concerned frown.

"That is correct," Yo said in a low voice and sighed. "By the looks of it, Donatello must have met him there and been unable to reach the safety of the manhole."

"I guess it's officially started then," the woman shook her head in dismay; she hugged her youngest son tight. Her soul mate just nodded looking very grave.

* * *

 **Elsewhere**

The Experimentor walked through the tunnel a bit hunched; he was so large that he couldn't walk completely straight. One hand clutched Tello's bloodied mask. The dark-brownish turtle was grim faced and muttered something to himself.

This was the second time he had stolen a mask from Donatello. He was currently wearing the first mask, but the second the large Black Turtle was going to deliver to his master.

Soon he entered a chamber; it was full of bones and rotten body parts. Elevated on a hill made of bones and bodies was a chair. On the chair sat the Dark One, his eyes narrowed when seeing the cousin enter and approach him.

"You were supposed to bring someone with you," the black-greenish turtle growled.

"His family came." The Experimentor kneeled at the bottom of the hill. His head was bowed. The hand with the mask rested on the stone floor.

"Yo," the Dark One growled. "Why does he keep resisting?"

The Experimentor didn't answer, he glanced at the mask and then up at his leader. Slowly the large turtle lifted his hand to show the indigo colored fabric. The navy-blue masked reptile scowled and then held out his hand. His underling climbed up the hill and gave the item to him.

"That is the mask he carried," the bigger turtle explained and backed down the hill.

"Donatello, yes I scent him. This is his blood." the Dark One nodded but then frowned. "Why can't I smell Yo from him?"

"What do you mean Master?" the Experimentor inquired, he was back in a kneeling position at the bottom of the hill.

"I can smell In, but not Yo. I can smell In and Yo from Leonardo. When we met their third son, I as well could smell them from him. But why not Donatello?" The leader carefully pulled the mask closer and sniffed at it.

"And he is different, he's taller and his color is darker. He as well has this raging temper that sometimes grabs hold on him." The Dark One frowned as he eyed his underling. "Leave me."

"As you wish Master," The Experimentor nodded and crawled away.

 **End chapter 1**

* * *

 **A/N:** At this point in time Splinter has passed on due to old age.


	2. Chapter 2

**A/N:** Chapter originally written on 23/05 2007

* * *

 **Chapter 2**

 **Yo and In's family**

 _"Who's there?"_ Tello looked around; so far he had been in a dreamless sleep. Suddenly he was aware of a presence.

 _"You are different,"_ a voice addressed him, deep and dark. Donatello froze when out of the darkness came the Dark One. The large turtle smiled devilishly.

 _"Wha…what are you doing here?"_ Tello asked startled and backed away.

 _"I'm reaching out; your mind is in a weakened state and thus easy to reach. I wished to see you."_ The black-greenish turtle then chuckled.

 _"Leave me now,"_ Donatello demanded but the Dark One didn't respond, just took a step forward.

* * *

Yo sat down by the infirmary bed. His son was still sleeping, all wrapped up in bandages to cover the many wounds he had received. The black-masked turtle intended to be there when Tello woke up.

Suddenly Donatello began whimpering in his sleep and shifting around. The older turtle took his son's left hand, but Tello kept whimpering and it was as if he was struggling against something. Yo frowned, this was not usual.

"No… no get back… leave me…" the younger reptile suddenly begged.

His father frowned now heavily. The older turtle closed his eyes and entered a meditative state, slowly reaching for his son's mind. He immediately picked up on the dark presence and gritted his teeth.

* * *

Yo found himself in a dark place but still could see his son clearly. He was backing away from someone. The older reptile frowned heavily when recognizing the Dark One.

 _"Leave my son alone, you have no right invading his dreams,"_ he called and immediately rushed to his son's side.

 _"Father."_ Tello reached for Yo as he approached. The Dark one frowned heavily.

 _"Son, you must wake up. That is the only way to rid yourself of this forced contact with the Dark One,"_ the older reptile informed Donatello.

 _"Wake up? How?"_ the younger turtle asked confused. Suddenly his father pushed him so he tripped…

* * *

Tello woke up with a start. He was too weak to rise up and could only lie. The turtle looked to his side to see his father sitting by the bedside, holding his left hand. Slowly Yo opened his eyes and smiled at his injured son.

"Often when you dream you're falling, you wake up," the elder reptile informed him.

"W-what happened there?" Donatello whispered. He squeezed his father's hand for comfort.

"Apparently the Dark One invaded your sleeping mind," Yo explained to him.

"He said he wished to see me." The younger turtle closed his eyes and sniffled. "F-father… I'm sorry…"

"Shh." His father reached out with his other hand to cup Tello's cheek gently.

"Your concern for your brother is understandable. You have seen and experienced what they can do. You were only trying to protect him, though your manner in doing so was a bit out of line." Yo let go of the cheek and sat up more properly. He never let go of his son's hand.

"I know… I was out of line. I just got so worried and…angry." Donatello gulped as he remembered the tortures.

"If I hadn't been so angry… I would have realized I wasn't alone in the factory. The Experimentor… he caught me completely by surprise." The injured turtle closed his eyes tight, few tears escaped through. "He was so… vicious… I just… he kept biting me… tearing at my wounds…"

"Shh, don't work yourself up Donatello, you should rest," Yo told his son gently. Tello nodded and opened his eyes a bit.

"I'm going to get you some water, you need fluids right now in your body," his father said and began rising up. The younger turtle reluctantly let go of his hand.

Yo had barely left the infirmary when Raphael snuck in. The purple masked turtle slowly approached the bed, but didn't meet his brother's eyes. With his head bowed Raph sat on the chair their father had previously occupied.

"Uh… hey," Raphael muttered.

"What happened to your arm?" Donatello asked when seeing the cast.

"The Experimentor broke it… I disobeyed father's orders. He told me to get you down into the manhole, but I instead only took you to it and rejoined the battle. The Experimentor managed to grab my arm and break it," the red-clad one explained.

"Raph… I'm sorry." Tello sighed heavily. "What I said earlier… I shouldn't have…"

"No it's ok Tello… I know you meant well. You always have been very protective of Mikey and me and with how I acted, you were probably right. I'm not ready." Raphael shook his head in dismay.

"You are ready, you just need to remember to follow orders," his brother said. "It's very important, Raphael, to follow the orders. It can mean the difference between life and death."

Yo returned holding a glass of water, he put it on the table near the bed and helped Tello to sit up. Then the older turtle gave the drink to his son, instructing him to drink it. The injured one did so but slowly.

"Raphael, leave us," the black-masked turtle told Raph who reluctantly rose up and left the infirmary, closing the door.

"He was right," Tello muttered and looked at his father, Yo stared at him questionably while sitting down.

"The Dark One… he was right… I am different." Donatello looked back down; he still held the glass and slowly turned it in circles.

"I mean Mother can show a temper if she is crossed badly… but never so fiery like mine… and look at me." The younger turtle glanced at where skin was visible on his body. "I'm darker than Mother and Raphael, we all share the same color but mine is darker. I'm the largest of all of you; in fact I've been the largest for over five years. Not to mention strongest."

Tello looked at Yo who never changed his calm expression. Donatello didn't expect any less of his father. The jonin was very much like his later father now, calm and stoic, hard to cross and anger. He would betray no emotions when needed.

"Does it really matter my son?" Yo finally ask. "You and your brothers are all different, we are all different. It does not change the fact that you are my son."

"I don't know… guess not… just still…" Donatello hung his head and closed the eyes. "Why would The Dark One reach out for me… just because The Experimentor almost took me to him? No… I don't think that fits…"

Yo didn't answer that one, now it did seem like he was thinking. Suddenly he stood up and put a hand on his son's shoulder.

"I'll be right back, my son," the older turtle said and let go, then he walked out of the room.

* * *

 **Somewhere unknown**

The Dark One walked into the big room and took a casual glance around. It looked rather like a cross between a butchers shop and mad scientist lab. Further, in the room, the resident of this ghastly place was working by a table. The Experimentor was busy with something and hadn't noticed his leader's entry.

"You wished to see me," The Dark One addressed the larger turtle. His underling turned slightly and smiled.

"I did," The Experimentor said and returned to the table. His leader was now by his side; on the table were various strange tools and many vials with blood.

"Well, what?" The Dark One inquired, the bigger reptile looked at him still smiling.

"I was thinking about something you said, that you didn't smell Yo from Donatello's blood," he said. The leader nodded remembering that well. He was still a little frustrated that Yo had arrived and interrupted his connection.

"When did In live with us, almost eighteen years? Nineteen?" the Experimentor inquired.

"Ah In, yes we enjoyed her company almost nineteen years ago or so," The Dark One confirmed with a nod.

"We? I recall you 'killed' the Brute two times for trying to approach her." The behemoth smirked causing his leader to chuckle.

"Well I do have my privileges as the leader." The smaller turtle shrugged but never dropped the smile.

"I gathered few samples from Donatello when I was playing with him." The Experimentor turned back to the original subject. "But now I need your blood as well."

"Why?" The Dark One frowned.

"Because Donatello is about eighteen years old," his underling explained.

The leader of the Black Turtles blinked for a moment as he took this in. Slowly he glanced up at The Experimentor. First, the reptile was unsure but slowly a smile began creeping across his beak. Then the smaller turtle laughed, very loudly and madly before grabbing a nearby rusty knife and cut a large wound on his arm. His underling immediately gathered the dripping blood before the wound quickly healed again.

"Cousin, you just made my day, hell, even made my week. I now truly hope this gives the result you were aiming for." The Dark One grinned strangely before begin leaving the lab. "Notify me when you have results."

"I will Master, I will," The Experimentor assured him before turning back to work.

* * *

 **Yo and In's family**

Yo returned to the infirmary after a while. Behind him came In and she closed the door as the two entered. Donatello frowned, his mother was carrying a very grave expression but his father was neutral.

"My son… we must talk," Yo said as he sat down in the previous chair. In fetched another one and placed it beside her soul mate. "Your mother and I… we discussed it and felt you are old enough to both know and perhaps understand."

"Know what?" Tello frowned in confusion. In sighed and looked down, her mate took her hand and gave it a gentle squeeze.

"Before I tell you, I want to know that for us it changes nothing. You are still our son and we love you and care for you. We would do anything to ensure your safety," his father began, first now did he show a sad expression.

"As you know your mother was captured by the Dark One many years ago. Your grandfather and I spent months trying to get her back, though it was hard since we already had your brother Leonardo to care for…"

"Wait, Leonardo was already born?" Tello asked surprised. He and his brothers knew well the many battles their parents had waged against the Black Turtles. However, this small fact was new to him, they were aware that In had spent time as their enemies captive, but they usually never got a timeframe for it.

"Uh sorry." Donatello realized that he had interrupted and hung his head a little.

"It's alright, there was a good reason why we never told that Leonardo was already born, he was in fact roughly four years old at the time," Yo continued, his son frowned more but this time remained silent.

"My son… I wasn't just the Dark One's captive," In spoke up but it was in a whisper. Slowly she looked up, her expression extremely sad. "When he had control over me… I was his mate."

"M-mate?" Tello slowly looked up and towards his mother. His parents didn't say anything more at the moment, but they didn't need to. Donatello was already piecing the puzzle together.

 _Wait… months captive… Leo four years old or so… she was his mate…_ the younger turtle's eyes slowly opened wide as the realization hit him.

"No," he whispered.

"I'm sorry that we kept this from you, my son," Yo said causing Tello to look straight at him.

"I'm not…" the injured reptile came to an abrupt halt. His parents waited, but had seen the brief flash of anger cross his eyes. However, this time Donatello managed to keep somewhat calm.

"Mother… can I speak with father alone?" their son requested.

In looked at her mate who nodded. The woman rose from her chair and looked at Tello with a weak smile before leaving the room. Yo managed to retain his calm expression and was ready for a storm. He would not blame the younger turtle for blowing up at those news.

"Thank you," Donatello whispered.

"For what?" the black-masked turtle asked, just barely managing to hide his confusion.

"For being my father, instead of him," his son explained and glanced down at his hands. "Thank you for getting mother out before she laid the egg. Raising me as your son and give me a better life than he could have given me."

"We did not care what your origins were. You were our son from the moment you were born and even when your mother was carrying the egg," Yo told him with a smile.

"Can we though… still keep it secret from my brothers? They don't need to know." Tello glanced towards the door warily. A hand was laid on his shoulder; Donatello looked at his father who had never dropped the smile.

"Of course, it will be from now entirely up to you if this is revealed or not. This is now something only you can tell about," the older turtle assured him.

"Thanks father," Tello now first smiled himself.

* * *

 **Elsewhere**

The Experimentor growled and slammed the smaller turtle the wall. His victim yelped and desperately tried to escape but the large reptile had a firm hold. The Weak One as he was called hissed, growled and struggled.

"I told you, keep away from my experiments!" the behemoth snapped and ended up throwing the other turtle screaming across the room. The very-dark bluish colored reptile crashed into the innermost wall crumbled to the floor.

"The Weak One causing trouble?" the Dark One inquired as he walked into the lab.

"He's always causing trouble," the Experimentor snarled and stalked back to his worktable. The leader followed him, but kept an eye on the smallest Black Turtle who was slowly crawling up to his feet.

"Yes, he's always been the odd one among us." The Dark One nodded and rubbed his chin before turning his attention to the larger turtle. "So you have the results."

"I have." His underling dropped the scowl and smirked.

"So, let's have it." The leader now stood beside the Experimentor at the table.

"I won't bore you with details, Donatello is yours," the big reptile told the smaller one.

The Dark One stood there in silence for a moment as he took it in. The turtle half folded his arms; one hand was slowly rubbing the chin. A wicked grin was slowly crossing his beak. Suddenly he laughed, loudly and madly.

"Keep this going cousin," he snickered and turned to leave. "And I might just promote you eventually to brother."

"That's what I'm aiming for," the Experimentor responded chuckling and watched his leader leave the lab, closely followed by the whining and complaining Weak One.

* * *

 **Yo and In's family**

Donatello yawned and put the notebook away. He was feeling better already, though still weak from the blood loss. The turtle lay down in the bed, having been allowed to sleep in his own room. Slowly the ninja drifted to sleep.

 _"Not you again."_ Tello had only been asleep for few seconds when he was once more pulled into the dark space. Right in front of him stood the Dark One.

For once the bigger and darker reptile was silent, just stood there with arms folded and regarded the smaller turtle. Donatello blinked in surprise; he had half expected something to be said. If anything, the Dark One always seemed to love the sound of his own voice. Suddenly the evil creature shook his head chuckling.

 _"It's been staring me in the face for years, odd to have been so blind to this,"_ the Dark One spoke finally.

 _"What?"_ Donatello slowly backed away to keep distance between them. He was ready to trip himself to try to wake up. The other turtle grinned, exposing the dangerously big sharp teeth in his mouth.

 _"You are taller than every member of your family. Your color is darker, you can take much more punishment, you heal quicker." T_ he black-greenish colored one counted up rather casually, never dropping the grin.

 _'Oh shit, he knows…'_ Tello cringed for a moment but sneered.

 _"Blab about it all you want, it will be a cold day in hell before I call you father,"_ he then snapped. The Dark One laughed and began to approach.

 _"Donatello, why deny it? You are already stronger, don't you want to be even stronger?"_ he whispered, the voice changing tone and becoming a bit more enchanting.

 _'Ooooh crap.'_ Donatello had not been aware that the Dark One could use the voice in a dream state, but now he was.

 _"Sorry, but I already have a father and he wears a black mask,"_ Tello sneered and was just about to trip himself, but suddenly the bigger turtle was right in front of him and had grabbed his shoulder. _'SHIT!'_

 _"Interesting, seems that you are resistant to the voice. Not many can brag about that, Donatello my son and I can sense it now,"_ the Dark One whispered and frowned. _"It seems I can't force you to me. You must come on your own free will."_

 _"Well forget that,"_ Donatello growled and tried to rip himself free from the iron grip.

 _"Pity, would have loved to rip you away from Yo right here and now. Looks like I'll have to do it on the physical plane or be patient, who knows one day you might just accept your fate,"_ the large turtle said and let go of Tello who fell to the ground.

Tello woke up with a start, sat up in the bed and put a hand on the chest. His heart was beating rapidly; the turtle breathed heavily and closed his eyes. Slowly and eventually, he managed to calm himself down.

"Accept my fate? Yeah right, up yours Dark One, I aint coming," the ninja snorted and lay back down. He was about to lie back down and try to sleep for real when there was a soft knock on the door. Tello turned on the night-lamp.

"Yeah?" he then glanced at the doorway that slowly opened. A small bluish-green head peeked in. Seeing that his big brother was awake, Mikey carefully sneaked in clutching his teddy bear.

"Tello?" the little turtle whispered as he approached the bed.

"What do you want, Squirt, why aren't you in bed?" Donatello asked.

"Can't sleep. Can I sleep here?" Mikey looked at his big brother pleadingly. Tello raised an eye-ridge but wasn't that surprised. Yo would only allow him to sleep in the parent's bed if the little turtle had a very bad nightmare and refused to go to sleep. Or was terribly sick and needed all the comfort he could get.

His brothers on the other hand had harder time to say no, Leo was probably the only one who was on the same level and their father. Raphael and Donatello just about melted at the sight of the big brown puppy dog eyes. Raph especially could just never say no to Mikey.

"Oh all right, climb aboard." Tello shifted closer to the wall to make room. Michelangelo climbed into the bed and lay down, so did his brother. The bigger turtle then drew the blanket over both of them.

Michelangelo was rather quick this time to fall asleep. However, Donatello found himself staring down at the six year old for a moment. A smile formed on his beak and he gently caressed his little brother on the cheek. Then put an arm protectively over the smaller reptile.

 _Yeah, brag about it all you want Dark One. I belong here and I already have a father, a mother and three brothers,_ he thought before drifting to sleep.

 **The end**

* * *

 **A/N:** As my character development process went on, I always kind of had Tello a bit of a mix between Donatello and Raphael. Tello is good with technology, but he won't fix up some miracle solutions or a gadget of the week to safe the day.


End file.
